Backport Chromium-Wayland upstream patches

This task has been an ongoing subtask of the different Chromium updates. After https://lf-automotivelinux.atlassian.net/browse/SPEC-3806#icft=SPEC-3806 the delta with upstream wayland is much smaller so we will not actively be doing these backports unless any knon-issue is raised.

Both pull requests:  https://github.com/webosose/chromium68/pull/17 and https://github.com/webosose/chromium68/pull/18 were accepted and the chromium68's recipe was updated accordingly both for master and halibut:  https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl-devel/+/22216

Effort to backport other patches is on-going. Keeping the issue open as this is a continuous task.

Ozone/wayland backports related to GBM can be found in pull request:

https://github.com/webosose/chromium68/pull/18

Specifically:

• [ozone/wayland] rely on implicit sync for Broadcom and Intel GPUs.
  https://chromium.googlesource.com/chromium/src/+/9624aabd50c58f12640797bd9b6ffb24efc1a4e2

• [ozone/wayland] Use gbm with in-process-gpu mode
  https://chromium.googlesource.com/chromium/src/+/a28b6de6cbbd0d30c2a88ccb29faa056000ff6be

The last one in the list fixes https://lf-automotivelinux.atlassian.net/browse/SPEC-2699#icft=SPEC-2699

Pull request was accepted.

Backports related to xkbcommon and other keyboard improvements and fixes in ozone/wayland can be found in pull request:

https://github.com/webosose/chromium68/pull/17

Specifically:

• ozone: xkbcommon: Pre-compute masks when setting keymap
  https://chromium.googlesource.com/chromium/src/+/0ff1d4acbad09f20e1606d3926c5ab7d7be722cd

• ozone/wayland: xkbcommon: Fix layout switching
  https://chromium.googlesource.com/chromium/src/+/efa8b4ba79261a1d84faaf382a25e01f7fc6210f

• ozone/wayland: Support NumLock in non-chromeos builds
  https://chromium.googlesource.com/chromium/src/+/3a1541f5115ec0d20b3a834dd2597acf4ca645af

• ozone/wayland: Remove WaylandXkbKeyboardLayoutEngine
  https://chromium.googlesource.com/chromium/src/+/219e3cba255e390615f340e72ca629c89bca993e

• ozone/wayland: Fix NEO keyboards layout handling
  https://chromium.googlesource.com/chromium/src/+/5f11c3164bbf8a49a5641d6d3186c93ec4c7fc85

• ozone/wayland: Support dead keys
  https://chromium.googlesource.com/chromium/src/+/878224922f634f248d48192b86dafde591d2faf8

• Move CharacterComposer into //ui/base/ime
  https://chromium.googlesource.com/chromium/src/+/f9877aee9a521c887751db85d3cf71db3af02d13

As a side note, the last two commits in the list fix https://lf-automotivelinux.atlassian.net/browse/SPEC-2746#icft=SPEC-2746